What CSV to JSON Converter helps you do

JSON is easier to feed into an API, script, or test fixture, but most spreadsheet exports arrive as CSV. This converter parses delimited text locally, turns the first row into object keys, and keeps values as strings unless you ask for numeric and boolean inference. It is a quick way to inspect the shape of a report before writing an importer.

Parsing and JSON generation run entirely in your browser. Pasted rows and dropped files are not uploaded to Haivix.

How it works

The text is parsed with the selected delimiter, respecting quoted fields and embedded line breaks. The first row becomes the keys and each later row becomes an object. Strings are preserved by default; inference converts numeric-looking and boolean-looking values while keeping leading-zero values as text. Duplicate header names are suffixed so keys stay unique.

How to use CSV to JSON Converter

Paste CSV or TSV data, or drop a file onto the upload area.
Choose a delimiter or leave Auto-detect on, then decide whether the first row is a header row.
Enable type inference only when numeric and boolean JSON values are wanted.
Copy or download the result and validate it before use.

When to use it

Turn an exported report into JSON for an API request or fixture.
Inspect how a CSV header row maps to object keys before writing an importer.
Convert a small spreadsheet into readable JSON without opening a code editor.
Create test data from a business-owned export.
Check a report's columns before handing it to a developer.
Move a small lookup table into a JSON config file.
Create seed data for a database or API test.

When not to use it

Do not use inference for identifiers that look numeric.
Do not convert a very large file in one pass if only a few rows are needed; filter it first.
Do not expect nested JSON; the output is a flat array of objects.

Example

A product export has sku, name, price and active columns. With inference on, price becomes a number and active becomes a boolean, while a SKU such as 007 stays a string. The result loads directly into a fixture without rewriting the identifiers.

What you can do with CSV to JSON Converter

Paste CSV or TSV data, or drop a file.
Auto-detect comma, semicolon, tab or pipe delimiters.
Use the first row as object keys.
Keep values as strings by default.
Optionally infer numbers and booleans.
Copy the JSON or download it as a .json file.

Example: build an API fixture

Paste the export and check the detected delimiter. A tab-separated file read as comma-separated produces one long key per row.

Leave inference off for identifiers, postal codes and phone numbers. Turn it on when the destination genuinely expects numbers and booleans.

Copy the JSON into the fixture or download it, then validate it with the JSON formatter before committing.

What to know before you start

Quoted fields and embedded line breaks follow RFC 4180-style rules; malformed quotes stop the conversion with an error.
Type inference is conservative and keeps leading-zero values such as 007 as text.
The output is an array of objects; duplicate header names are suffixed so keys stay unique.
There is no nested-object or array parsing.
Very large inputs are limited by browser memory.

Common mistakes

Enabling inference and turning a leading-zero SKU into a number.
Leaving a blank header cell, which produces an empty or duplicated key.
Choosing the wrong delimiter and getting one key per row.
Copying the JSON without checking for nulls or empty strings.
Assuming quoted line breaks are supported without checking the source.

Troubleshooting

If every row becomes a single key, the delimiter is wrong. Try comma, tab, semicolon or pipe.

If the conversion stops on a quote, the source has a malformed quoted field. Fix the quoting and try again.

If a number lost its leading zeros, disable inference and export it as text.

If keys are suffixed, the header row contains duplicate names; rename them for a cleaner result.

If the output is huge, filter the rows or columns before converting.

If a numeric-looking identifier changes, inference was enabled. Disable it and regenerate so the JSON preserves the identifier as a string, which is what most APIs and databases expect for account, order and postal codes.

If a header contains a space or punctuation, the key keeps it. That is valid JSON, but a consumer may expect camelCase; rename the header before converting when the schema is strict.

CSV to JSON Converter